import React, { Component } from 'react'

export default class App extends Component {
  state = {
    count: 100
  }

  render() {
    return (
      <div>
        <button
          onClick = {() => {
            this.setState({
              count: this.state.count + 1
            })
          }} 
        >加</button> { this.state.count }
      </div>
    )
  }
}
